"We don't know how the first $380 million has even been spent, and the intelligence committee did an extensive research on how much money was needed and the $380 million amount was what was needed for the moment," he said.

Leahy fired back that the "lights are blinking red" and Congress should approve more money before the election.

"The president is not going to act. The duty has fallen to us. Let's not after an election find out that this country was defenseless against attacks from Russia and say oh, gosh, we should have done something," Leahy said.

The Senate fight over election security comes as lawmakers are signaling that they are increasingly concerned that Russia will try to interfere in the 2018 election.